A problem that can occur when an inexperienced bowler is bowling is that the bowling ball leaves the bowling lane and falls to the gutter so often that bowling is no longer inspiring. Therefore, obstacles have been developed for bowling lanes by means of which the falling of the bowling ball from the track to the gutter travelling on the side of the track is prevented. This form of bowling, in which the drifting of the bowling ball into the gutter is prevented, is called bumper bowling in English. There is no established Finnish term for this purpose. Because the Finnish terms related to bowling lanes are otherwise unestablished to a certain extent as well, corresponding English terms are shown in parenthesis in this application.
Usually the falling of the bowling ball into the gutter has been prevented either by moving the edge of the gutter in such a manner that it forms an obstacle for the bowling ball or by moving a separate obstacle located between the bowling lane and the gutter.
Obstacles that are formed in the edge of the bowling lane are disclosed for example in the publications U.S. Pat. Nos. 5,564,986, 5,857,918, 5,681,224, 5,417,616, 5,380,251 and 5,304,097.
Publication U.S. Pat. No. 5,304,097 discloses a lane suitable for conventional bowling or bumper bowling, in which the obstacle is formed by means of compatible beams parallel to the longitudinal or lateral direction of the lane.
The publication U.S. Pat. No. 5,380,251 discloses a fence-like obstacle, which can be lifted up in parallel with the lane by means of beams extending underneath the gutter.
The publication U.S. Pat. No. 5,417,616 discloses an obstacle, which is formed when the other side of a gutter composed of two parts is lifted up by means of a lever arm and a spring.
The publication U.S. Pat. No. 5,564,986 discloses an obstacle, which is formed when the gutter is lifted up by means of a torsion shaft.
The publication U.S. Pat. No. 5,681,224 discloses an obstacle, the movement of which is effected by means of a hydraulic cylinder. The hydraulic cylinder is guided either manually from the control panel of a score keeping device or by means of an electronic control circuit.
The publication U.S. Pat. No. 5,857,918 discloses an obstacle, which is formed when the other side of a gutter composed of two parts is lifted up by means of air cylinders or another electromechanical system. The air cylinders cushion the mechanical stress exerted to the obstacle when the obstacle is lowered down.